Merge pull request eugenp#8141 from JonCook/master

BAEL-3375 - Get the current Date in Java (non Java 8)

Author: JonCook

core-java-modules/core-java-date-operations/pom.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <artifactId>core-java-date-operations</artifactId>
+    <version>${project.parent.version}</version>
+    <packaging>jar</packaging>
+
+    <parent>
+        <groupId>com.baeldung</groupId>
+        <artifactId>parent-java</artifactId>
+        <version>0.0.1-SNAPSHOT</version>
+        <relativePath>../../parent-java</relativePath>
+    </parent>
+
+</project>

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/datetime/CalendarUtils.java

@@ -0,0 +1,15 @@
+package com.baeldung.datetime;
+
+import java.text.ParseException;
+import java.util.Calendar;
+import java.util.Date;
+
+public class CalendarUtils {
+
+    public static Calendar getPlusDays(Date date, int amount) throws ParseException {
+        Calendar calendar = Calendar.getInstance();
+        calendar.setTime(date);
+        calendar.add(Calendar.DAY_OF_YEAR, amount);
+        return calendar;
+    }
+}

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/datetime/DateUtils.java

@@ -0,0 +1,20 @@
+package com.baeldung.datetime;
+
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+import java.util.Date;
+
+public class DateUtils {
+
+    public static Date getNow() {
+        return new Date();
+    }
+
+    public static Date getDate(long millis) {
+        return new Date(millis);
+    }
+
+    public static Date getDate(String dateAsString, String pattern) throws ParseException {
+        return new SimpleDateFormat(pattern).parse(dateAsString);
+    }
+}

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/datetime/sql/DateUtils.java

@@ -0,0 +1,21 @@
+package com.baeldung.datetime.sql;
+
+import java.sql.Date;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+public class DateUtils {
+
+    public static Date getNow() {
+        return new Date(System.currentTimeMillis());
+    }
+
+    public static Date getDate(String dateAsString) {
+        return Date.valueOf(dateAsString);
+    }
+
+    public static Date getDate(String dateAsString, String pattern) throws ParseException {
+        java.util.Date customUtilDate = new SimpleDateFormat(pattern).parse(dateAsString);
+        return new Date(customUtilDate.getTime());
+    }
+}

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/datetime/sql/TimeUtils.java

@@ -0,0 +1,21 @@
+package com.baeldung.datetime.sql;
+
+import java.sql.Time;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+public class TimeUtils {
+
+    public static Time getNow() {
+        return new Time(System.currentTimeMillis());
+    }
+
+    public static Time getTime(String timeAsString) {
+        return Time.valueOf(timeAsString);
+    }
+
+    public static Time getTime(String dateAsString, String pattern) throws ParseException {
+        java.util.Date customUtilDate = new SimpleDateFormat(pattern).parse(dateAsString);
+        return new Time(customUtilDate.getTime());
+    }
+}

core-java-modules/core-java-date-operations/src/main/java/com/baeldung/datetime/sql/TimestampUtils.java

@@ -0,0 +1,21 @@
+package com.baeldung.datetime.sql;
+
+import java.sql.Timestamp;
+import java.text.ParseException;
+import java.text.SimpleDateFormat;
+
+public class TimestampUtils {
+
+    public static Timestamp getNow() {
+        return new Timestamp(System.currentTimeMillis());
+    }
+
+    public static Timestamp getTimestamp(String timestampAsString) {
+        return Timestamp.valueOf(timestampAsString);
+    }
+
+    public static Timestamp getTimestamp(String dateAsString, String pattern) throws ParseException {
+        java.util.Date customUtilDate = new SimpleDateFormat(pattern).parse(dateAsString);
+        return new Timestamp(customUtilDate.getTime());
+    }
+}

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/datetime/CalendarUtilsUnitTest.java

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+package com.baeldung.datetime;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import com.baeldung.datetime.CalendarUtils;
+import com.baeldung.datetime.DateUtils;
+
+import java.text.ParseException;
+import java.util.Date;
+
+public class CalendarUtilsUnitTest {
+
+    @Test
+    public void givenDateAndDaysToAdd_thenCalendarIsCorrectlyReturned() throws ParseException {
+        Date initialDate = DateUtils.getDate("2020/01/01", "yyyy/MM/dd");
+        Date expectedDate= DateUtils.getDate("2020/01/11", "yyyy/MM/dd");
+        assertEquals(expectedDate, CalendarUtils.getPlusDays(initialDate, 10).getTime());
+    }
+}

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/datetime/DateUtilsUnitTest.java

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+package com.baeldung.datetime;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import com.baeldung.datetime.DateUtils;
+
+import java.text.ParseException;
+import java.util.Date;
+
+public class DateUtilsUnitTest {
+
+    @Test
+    public void givenTimeMillis_thenDateIsReturned() {
+        Date now = DateUtils.getNow();
+        assertEquals(DateUtils.getDate(now.getTime()), now);
+    }
+
+    @Test
+    public void givenDateAndPattern_thenDateIsCorrectlyReturned() throws ParseException {
+        long milliseconds = new Date(2020 - 1900, 0, 1).getTime();
+        assertEquals(DateUtils.getDate(milliseconds), DateUtils.getDate("2020/01/01", "yyyy/MM/dd"));
+    }
+}

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/datetime/sql/DateUtilsUnitTest.java

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+package com.baeldung.datetime.sql;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import com.baeldung.datetime.sql.DateUtils;
+
+import java.text.ParseException;
+import java.util.Date;
+
+public class DateUtilsUnitTest {
+
+    @Test
+    public void givenCurrentDate_thenTodayIsReturned() {
+        assertEquals(DateUtils.getNow(), new Date());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void givenDateAsString_whenPatternIsNotRespected_thenExceptionIsThrown() {
+        DateUtils.getDate("2020 01 01");
+    }
+
+    @Test
+    public void givenDateAndPattern_thenDateIsCorrectlyReturned() throws ParseException {
+        assertEquals(DateUtils.getDate("2020-01-01"), DateUtils.getDate("2020/01/01", "yyyy/MM/dd"));
+    }
+}

core-java-modules/core-java-date-operations/src/test/java/com/baeldung/datetime/sql/TimeUtilsUnitTest.java

@@ -0,0 +1,28 @@
+package com.baeldung.datetime.sql;
+
+import static org.junit.Assert.assertEquals;
+
+import org.junit.Test;
+
+import com.baeldung.datetime.sql.TimeUtils;
+
+import java.text.ParseException;
+import java.util.Date;
+
+public class TimeUtilsUnitTest {
+
+    @Test
+    public void givenCurrentTime_thenNowIsReturned() {
+        assertEquals(TimeUtils.getNow(), new Date());
+    }
+
+    @Test(expected = IllegalArgumentException.class)
+    public void givenTimeAsString_whenPatternIsNotRespected_thenExceptionIsThrown() {
+        TimeUtils.getTime("10 11 12");
+    }
+
+    @Test
+    public void givenTimeAndPattern_thenTimeIsCorrectlyReturned() throws ParseException {
+        assertEquals(TimeUtils.getTime("10:11:12"), TimeUtils.getTime("10 11 12", "hh mm ss"));
+    }
+}